多細胞生物不需要氧氣

多細胞生物不需要氧氣

　　科學(xué)家在深海底發(fā)現奇怪的生物，它們已經(jīng)適應了極端環(huán)境，可以在完全無(wú)氧的狀態(tài)下生存。

　　As scientists delve deeper beneath the ocean’s surface, they find bizarre creatures that have adapted to harsh and extreme environments. Now comes a new one—the discovery of the first multicellular animals that survive and reproduce entirely without oxygen. [Roberto Danovaro et al, BMC Biology, http://bit.ly/dcICgo]

　　Researchers had thought that only single-celled organisms such as prokaryotes and protozoa could live in the oxygen-deprived environments of the deepest ocean. When scientists did find multicellular organisms, they assumed that they’d sunk from oxygen-enriched waters.

　　But over the past decade, scientists in Italy and Denmark sent three expeditions to fetch samples from sediment in what’s known as a deep hypersaline anoxic basin in the Mediterranean. And in these sediments, from almost two miles below the ocean’s surface, they found three distinct species of a tiny multicellular animal phylum called Loricifera.

　　They don’t have mitochondria. Instead, they seem to have organelles that resemble hydrogenosomes—similar to mitochondria, but that use anaerobic chemistry. Scientists don’t yet fully understand the biochemistry—but the discovery opens the possibility of complex life forms on oxygen-free planets.

　　—Cynthia Graber

　　[The above text is an exact transcript of this podcast.]

　　1.delve[delv] vi. 探究，查考，挖掘

　　She delved in her bag and pulled out a pen.

　　她在提包里翻找，拿出一枝鋼筆。

　　2.bizarre[bi'zɑ:] adj. 奇異的，怪誕的 n. 奇異花

　　The story has a certain bizarre interest.

　　這個(gè)故事聽(tīng)起來(lái)別有風(fēng)趣。

　　3.multicellular adj. 多細胞的

　　4.organism n. 生物體，有機體

　　Germs may invade the organism.

　　細菌會(huì )侵入有機體。

　　5.expedition n. 遠征，探險隊，迅速

　　They planned to organize a scientific expedition.

　　他們計劃組織一次科學(xué)考察。

　　6.organelle n. 細胞器官

　　7.anaerobic adj. 厭氧的